Using a functional near-infrared spectroscopy (fNIRS) device, researchers have successfully measured how the brain synchronizes a conversation between two or more people, according to a paper published online February 27 in Scientific Reports, one of the Nature journals.
Researchers from Drexel University partnered with Princeton University psychologists to develop a headband-like fNIRS system that uses light to measure neural activity during real-life situations. The technology can be used to study scenarios ranging from doctor-patient communication to how people watch TV, according to a release from Drexel.
The study is based on previous research from Uri Hasson, PhD, an associate professor at Princeton, who used functional MRI to investigate how the brain deals with the production and comprehension of language. Hasson found that a listener's brain activity mirrors the speaker's brain when he or she is taking about a real-life experience.
The use of fMRI is limited, however, because the modality requires that subjects stay motionless in a noisy scanning environment. Therefore, it is not possible to simultaneously scan the brains of multiple individuals who are speaking face to face.
For this paper, the researchers asked a native English speaker and two native Turkish speakers to tell an unrehearsed, real-life story in their native language. Their stories were recorded and they were scanned using fNIRS. Next, 15 English speakers listened to the recording and also a story that was recorded at a live storytelling event.
The portable fNIRS device specifically targeted the prefrontal and parietal areas of the brain, which are associated with a person's ability to discern beliefs, desires, and goals of others. The researchers hypothesized that a listener's brain activity would correlate with the speaker's only when listening to a story in the language the listener understood.
They found that the listeners' brain activity matched only with the English speakers. The results also correlated with fMRI data from a similar, previous study.
Based on the findings, fNIRS could potentially be used to study brain-to-brain coupling during social interaction, and to provide information about how to better communicate in many different environments, the group concluded.
